The genie is a slave: it resents being used for its abilities by punny mortals, so it screws them over however it can.
The genie is alien: it doesn’t understand what humans actually mean, so it takes them literally when it interprets their wish.
The genie is malicious: it wants to hurt you and probably escape its confinement, or sees you as a tool to do evil.
The genie is a pedant: it deliberately only grants the letter of the wish, regardless of consequences, for whatever reason.
The genie is a dick: he doesn’t like you and enjoys goading, trolling, and generally fucking with you for its own amusement.
The genie is just following the rules: whatever force traps the genie requires it to be like this. Maybe whatever trapped it decided, or the rules of god, its society, or its nature force its behavior.
Here’s some options.
1, 3, 5: Jackass genie
2, 4, 6: Literal genie
Yeah, but I feel like calling a rebellious slave a jackass isn’t quite right.
One can be a jackass for justified reasons.